Wal-Mart retakes the No. 1 slot on the Fortune 500 this year. See where America's largest corporations rank, and why.

The insurer pulled off the biggest real estate deal in history with the sale of its 80-acre New York City apartment complex for $5.4 billion. Record revenues in its insurance
division helped the company grow the top line by 13% over last year, and profits to expand 34% to $6.3 billion.